There is better news for otters, though.
Their numbers have dropped dramatically over the last 100 years, but thanks to conservation projects, the report says they are now returning to many parts of the UK.
Efforts to save the water vole are also proving successful.
The report, by Oxford University's Wildlife Conservation Research Unit, contains some worrying findings about GM crops.
Research showed that fewer insects lived among GM crops.
Many creatures, including mice, bats and hedgehogs, need to snack on insects to survive.